1. Department of Otorhinolaryngology, Head and Neck Surgery, University of Toyama, Toyama, Japan
2. Department of Otorhinolaryngology, Toyama Red Cross Hospital, Toyama, Japan
3. Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, Nara, Japan
4. Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto, Japan